U.S. patent number 4,164,673 [Application Number 05/869,594] was granted by the patent office on 1979-08-14 for bearing made of stamped (embossed) sheet iron.
This patent grant is currently assigned to Societe de Paris et du Rhone. Invention is credited to Alfred B. Mazzorana.
United States Patent |
4,164,673 |
Mazzorana |
August 14, 1979 |
Bearing made of stamped (embossed) sheet iron
Abstract
A "bell-shaped" type of bearing of swaged sheet metal in the
form of a container bordered by a cylindrical skirt having a
central duct for the accommodation of a bearing bush is held to a
rotor magnetic circuit of an electric machine by at least two tie
rods passing through the bearing in a direction substantially
parallel to the axis of the duct for the bushing. The support zones
on the bearing against which the heads of the tie rods abut are
provided with at least one swaged rib extending continuously across
and between the zones and up to the skirt of the bearing to form a
box girder.
Inventors: |
Mazzorana; Alfred B.
(Venissieux, FR) |
Assignee: |
Societe de Paris et du Rhone
(Lyons, FR)
|
Family
ID: |
9185800 |
Appl.
No.: |
05/869,594 |
Filed: |
January 16, 1978 |
Foreign Application Priority Data
|
|
|
|
|
Jan 18, 1977 [FR] |
|
|
77 01833 |
|
Current U.S.
Class: |
310/89;
310/90 |
Current CPC
Class: |
H02K
5/15 (20130101); F16C 35/02 (20130101) |
Current International
Class: |
F16C
35/02 (20060101); F16C 35/00 (20060101); H02K
5/15 (20060101); H02K 005/00 (); F16C 035/00 () |
Field of
Search: |
;308/15,30,237R,245
;310/68D,89,90 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Frankfort; Charles E.
Attorney, Agent or Firm: Browdy and Neimark
Claims
We claim:
1. A bell-shaped type swaged sheet metal bearing in the form of a
container bordered by a cylindrical skirt intended to be supported
by at least two assembly tie rods on a shoulder of a rotor magnetic
circuit, the bearing comprising a central duct adapted to
accommodate a bearing bushing, at least one swaged rib integral
with said skirt, having two ends and having two respective
apertured areas near respective ones of said ends for the passage
and support of the assembly tie rods, said rib extending without
loss of continuity between said apertured areas and extending
outwardly up to said cylindrical skirt beyond said aperture areas
so as to form at least one box girder, said ends of said rib being
substantially coplanar with said skirt.
2. A bearing in accordance with claim 1, in which only two tie rods
are provided in diametrically opposite said apertured areas of said
swaged rib, having a central section in the shape of a cupola
having a cylindrical edge, said cylindrical edge being concentric
with said central duct.
3. A bearing in accordance with claim 2, in which said cylindrical
edge of said central cupola-shaped section of the bearing is
connected to said cylindrical skirt of the bearing by a section
shaped as a truncated cone, whereby rigidity of the bearing is
further improved.
4. A bearing in accordance with claim 2, in which to provide
accommodation for the heads of the tie rods, support zones are
provided at said ends of said rib and have an end fitting, a
vertical wall of which constitutes both an element connecting said
ends opposite said cylindrical edge of said central cupola-shaped
section of said rib and an element stopping rotation of a head of a
corresponding tie rod.
5. A bearing in accordance with claim 2, in which at the level of
tie rod support zones, that is at said ends of said rib, side
vertical walls of said rib, located on either side of apertures
provided for passage of the tie rods, are arranged as near as
possible to one another and at a distance less than the width of
the heads of the tie rods.
6. A bearing in accordance with claim 2, in which for better
distribution of the loads, the diameter of said central
cupola-shaped section of said rib is substantially equal to the
distance between centers of the assembly tie rods.
7. A bearing in accordance with claim 6, in which to provide
accommodation for the heads of the tie rods, support zones are
provided at said ends of said rib and have an end fitting, a
vertical wall of which constitutes both an element connecting said
ends opposite said cylindrical edge of said central cupola shaped
section of said rib and an element stopping rotation of a head of a
corresponding tie rod.
8. A bearing in accordance with claim 6, in which at the level of
tie rod support zones, that is to say at said ends of said rib,
side vertical walls of said rib, located on either side of
apertures provided for passage of the tie rods, are arranged as
near as possible to one another and at a distance less than the
width of the heads of the tie rods.
9. A bearing in accordance with claim 6, in which said cylindrical
edge of said central cupola-shaped section of the bearing is
connected to said cylindrical skirt of the bearing by a section
shaped as a truncated cone, whereby rigidity of the bearing is
further improved.
10. A bearing in accordance with claim 1, in which at the level of
tie rod support zones, that is at said ends of said rib, side
vertical walls of said rib, located on either side of apertures for
passage of the tie rods, are arranged as near as possible to one
another and at a distance less than the width of the heads of the
tie rods.
Description
This invention relates to a "bell-shaped" type of bearing made of
swaged sheet metal, that is to say shaped in the form of a
container bordered by a cylindrical skirt intended to be supported
by at least two assembly tie rods on a shoulder on a rotor magnetic
circuit and comprising a central duct intended to take a bushing of
the bearing.
Assembly of this type of bearing on the rotor magnetic circuit is
effected by means of tie rods traversing this bearing between the
central duct and the cylindrical skirt and which are therefore
necessarily off-set in relation to the magnetic circuit
shoulder.
The result is the formation of a couple which tends to deform the
bearing. Now, this deformation may involve misalignment of the
bearing bushing compared with the bushing of the other bearing, the
result of which may be not only bad centering of the armature in
relation to the rotor but in addition friction forces ending up
with premature wearing of the bushings.
This invention is intended to overcome these disadvantages.
For this purpose, the zones provided for the passage and support of
the assembly tie rods are provided with at least one swaged rib
connecting them without loss of continuity and extending up to the
cylindrical skirt so as to form at least one box girder.
This rib reinforces the rigidity of the bearing and eliminates
practically any risk of bending under the action of the assembly
tie rods.
In one simple embodiment of the invention, where only two tie rods
are provided in diametrically opposite zones, in its central
section, the swaged rib has the shape of a cupola, the cylindrical
edge of which is concentric with the central duct.
Advantageously, to give a better distribution of the loads, the
diameter of the cupola-shaped central section of the rib is largely
equal to the distance between centers of the assembly tie rods.
As a result of another advantageous characteristic of the
invention, again to improve the rigidities of the bearing, the
cylindrical edge of the container-shaped central section of the rib
is connected to the cylindrical skirt of the bearing by a section
shaped like the frustum of a cone.
To provide accommodation for the heads of the tie rods, in
accordance with another characteristics of the invention, the
support zones for the tie rods provided at the ends of the rib have
an end fitting, the vertical wall of which constitutes an element
for connecting the ends opposite the cylindrical edge of the
cupola-shaped central section of the rib. This not only gives an
improvement in the rigidity of the bearing, but in addition the
aforementioned vertical wall may be used to advantage to stop
rotation of the head of the tie rod.
Whatever the circumstances the invention will be well understood
from the description which follows, with references to the drawings
attached hereto, showing as a non-exhaustive example, an embodiment
of a swaged sheet metal bearing:
FIG. 1 is an elevation of its outside face;
FIG. 2 is a section view along 2--2 of FIG. 1;
FIG. 3 is an elevation of its inside face.
A swaged sheet metal bearing is of the type shaped like a container
with a bottom 2 surrounded by cylindrical skirt 3 at the center of
which a cylindrical duct 4 is provided, intended to accommodate a
bearing bushing 5.
The free edge of cylindrical skirt 3 is intended to be supported on
a shoulder 6 of rotor magnetic circuit 7, and the assembly is held
by means of tie rods 8. These tie rods cross the bearing in a zone
which must be located between skirt 3 and central duct 4, and
preferably as close as possible to cylindrical skirt 3. In fact,
the head 8a of the tie rods being supported on bottom 2 of the
bearing necessarily causes a tilting stress since force F which it
causes must be displaced transversely in relation to cylindrical
skirt 3.
It can be perceived easily that this force F tends to deform the
bottom of bearing 2, which may be the cause of a number of
disadvantages such as the misalignment of bushings 5, particularly
in the case of uneven tightening of the tie rods, the
bringing-together of two bushings assembled on one and the same
armature, friction force causing premature wear, de-centering of
the rotor in relation to the armature, hence operation under bad
conditions.
In accordance with the invention, zones 9 provided for the passage
and support of tie rods 8, are provided in at least one rib 10
swaged on the bearing, connecting the said zones without loss of
continuity. Where only two tie rods are provided located at
diametrically opposite points, rib 10 extends radially in bottom 2
of the bearing.
As shown on the drawing, this rib 10 extends beyond zones 9 up to
cylindrical skirt 3 to which is connected preferably with a slope
forming a rake or clearance, as illustrated at 11 on the
drawing.
As the drawing shows, in order to avoid difficulty due to the
presence of central duct 4 and to ensure better distribution of the
stresses in the bearing, the central section of rib 10 has the
shape of a cupola 10a, the cylindrical edge 10b of which is
concentric with central duct 4.
The bending strength conditions of bearing bottom 2 are obtained by
giving cupola 10a a diameter largely equal to the distance between
centers of tie rods 8.
To improve the rigidity of bearing bottom 2, the edge of cupola 10a
forming the central section of rib 10 is connected to cylindrical
skirt 3 of the bearing by a section 12 having the shape of a
truncated cone, the presence of which has the effect of increasing
the resistance to bending of bearing bottom 2.
Preferably, to avoid any weakening of the bottom of the rib due to
the pressure exercised by assembly tie rods 8, side vertical walls
15 of rib 10 on either side of the holes provided for the passage
of tie rods 8 are arranged as near as possible to each other and in
any case at a distance less than the width of heads 8a of tie rods
8. Therefore, the tension of tie rods 8 is supported directly by
walls 15.
To improve further the resistance to bending of the bottom of this
bearing, support zones 9 for heads 8a of tie rods 8 are provided in
swaged bottom 13, the vertical wall 14 of which constitutes a
stiffening element connecting the ends of opposed part-cylindrical
edges 10b of cupola 10a. This vertical wall 14 may in addition be
used to advantage to constitute an element stopping the rotation of
the corresponding head 8a of tie rod 8.
Tests carried out with this bearing and compared with tests carried
out with other well-known bearings have shown the manifest
superiority of its resistance to bending and, consequently, to
deformation.
Finally, by selecting a measuring point located on bearing bottom 2
near central duct 4, it was possible to find what with equal axial
load F, the deformation of the bearing in accordance with this
invention is at least four times less than that measured on the
least deformable bearings known at present and ten to twenty times
less than that of a bearing with a simple structure comprising for
example, simply a cylindrical skirt and a flat bottom, and this
applies even if two bosses are provided to serve as a support for
the heads of the assembly tie rods.
As is obvious and as can be seen from the foregoing, the invention
is not limited to the sole embodiment of this bearing described as
a non-limiting example, on the contrary it also covers any
variants.
* * * * *